Purpose: :
Perivenular whitening (PVW) may be observed in a subset of patientswith central retinal vein occlusion (CRVO). It is believed thatPVW is related to acute retinal ischemia due to hypoperfusion.Here, we report the contribution of high resolution opticalcoherence tomography (OCT) to locate PVW within the retina.

Methods: :
The charts of four consecutive patients (aged 28 to 58 years;duration of symptoms 1 to10 days) with CRVO with PVW, seen ata single university-based ophthalmological center for whichspectral domain OCT has been performed at the acute phase, werereviewed. The main outcome measure was the location of the PVWwithin retinal layers.

Results: :
Areas of patchy opacification of the inner nuclear layer wereobserved, involving also the inner plexiform layer in one cases.The outer nuclear layer and the nerve fiber layer were unaffected.During follow-up, diffuse thinning and irregularity of the Outerplexifor layer (OPL) and Inner nuclear layer (INL) developedin all patients, extending beyond the area initially involvedin PVW.

Conclusions: :
PVW is the fundoscopic manifestation of sectorial ischemic opacificationprimarily affecting the inner nuclear layer. The visual sequeleapresented by these patients may be due to secondary atrophyof the INL